Fear and Loathing of the Help Menu: A Usability Test of Online Help
http://www.ingentaconnect.com/content/stc/tc/1998/00000045/00000002/art00004
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  peer-reviewed

Grayling, Trevor
Technical Communication Online
1998

Abstract:

A usability test of online Help for a Windows-based database-searching application showed that test subjects avoided the Help menu for as long as possible. When finally obliged to use Help, they read the information carelessly and bailed out quickly, even without finding the necessary information. On the other hand, the test subjects did use dialog-box Help and pop-up Help for tools. The article identifies three qualities and two requirements that are apparent in dialog-box Help and pop-up Help for tools but which are not shared by the Help menu. It suggests that these qualities and requirements may make any Help access method that contains them attractive to users. It then goes on to examine dialog-box Help, pop-up Help for tools, and several other Help access methods, that use these qualities and requirements.